This invention relates generally to apparatus for the electrostatic transfer of a developed image from a first surface to a second receiving surface. More specifically, it relates to the cable tensioning system that works cooperatively with a web on which the developed image is found to insure the dimensional integrity of the transferred image.
Photoelectrophoretic copying machines have used webs that have been either continuous or of finite length stretched between two locations to produce copies of transferred developed images. Early systems utilized an intermediate web in an electrographic copying machine to produce copies by employing a cartridge formed of two molded shells that contained a supply of intermediate web wound between two rollers. The cartridge was removably mounted on a movable carriage to move between exposing, developing, and transferring stations.
Other early copy equipment used a system to transfer images on a support web to a xerographic belt by matching the speed of the transport belt with the xerographic belt to avoid blurring the transferred toner images.
These prior art systems were all affected by the relative speeds of the belts between which the transferred toner images moved, the amount of tension maintained on the belts by guide rollers to insure uniform tension, and any disturbing impacts or vibrations in the belt during movement about the guide rollers from one position to another as the images were transferred. Little concern was given to the potential for distortion of the full-sized image in the transfer from one belt to another belt or to an intermediate surface. This distortion is caused by slack in the belt and differences in the length of the web from an anchoring point on the copy apparatus to each discrete point of image transfer when the transfer is effected by some movable transfer means bringing the transferring and receiving surfaces into close proximity or contact as the transfer means traverses the length of the web or belt.
These problems are solved in the design of the Present invention by the use of an improved tensioning system for a web or belt in an electrostatic transfer system that employs a tensioning cable in conjunction with the web. The tensioning cable is connected to that web on one end and anchored to the transfer apparatus on an opposing second end.